When the application starts it shows a Welcome window. Here you can select a folder that has been scanned before by double-clicking it in the list of recently scanned folders. Alternatively, you can select another folder by clicking Scan Other Folder. After you have selected a folder, the folder is scanned to determine the size of all files in it (including the files in sub-folders). Once the scanning is finished a tree map of the scanned folder is shown in a new view window.

There are other ways in which you can create a view:

• The Scan Folder command from the "File" menu lets you scan any folder you choose.
• The Scan Recent sub-menu in the "File" menu lets you quickly scan a folder you scanned before. It will scan the folder without a filter, irrespective of how it was scanned previously.
• The Filtered Scan command from the "File" menu lets you scan a folder while immediately applying a filter. This way you can for example exclude sub-folders that you are not interested in, which may significantly speed up the time it takes to perform the scan.
• The Refresh command from the "File" menu or toolbar lets you quickly generate an up-to-date version of the current view. This is useful when the folder contents have changed, for example because you deleted one or more files. It only rescans the folders that have changed, according to file system events generated by macOS.
• The Rescan command from the "File" menu also lets you generate an up-to-date version of the current view. It performs a full scan so is slower than a refresh but can be more accurate (see refresh and rescan). You have the option to rescan the entire view or only part of it.
• The Load Scan Data command from the "File" menu lets you create a view with scan data that has been saved at an earlier moment.
• The Duplicate command from the "Window" menu lets you duplicate the current view. A new view is created similar to the current one. You can subsequently change its display settings to see the tree map in different ways at the same time.
• The Twin command from the "Window" menu lets you twin the current view. Twinning a view is very similar to duplicating it, except that navigation is synchronized as well.
• The Filter command from the "Window" menu lets you apply a filter to the current view.

In the Preferences window you can configure what should happen when the last view window closes:

• Show the Welcome window again
• Quit the application
• None of the above